The invention generally relates to a process in which a food product to be packaged is converted from a soft, fluid-like state to a firmer state in two or more stages. More specifically, the passage of the food product through these stages is useful to provide the food product with desired flow characteristics as it moves through the packaging equipment, and for obtaining the desired finished product body and texture.
Food products which are fluid during processing, such as jelly, food sauces, and dessert gels, may be difficult to process or package. For example, if the food product is extruded, or is required to pass over rollers, its passage through a packaging machine may be physically impeded if the viscosity of the food product is too low (see, e.g., FIG. 5), also causing problems with proper weight control of the packages. Conversely, the product body and texture may be physically damaged if the viscosity is too high, as further described below.
It is known to add a thickener, such as a consumable gel, to food products. See, e.g., U.S. Pat. No. 5,567,454 to Bogdan, disclosing the use of gelatin, fruit pectin and food starch to provide jelly with xe2x80x9coptimal flexibility and shape-retaining qualitiesxe2x80x9d (col. 6, lines 12-14), and also disclosing a recessed container in which the finished product shape may be formed. However, food gels have typically been allowed to form in an undisturbed state in order to gel properly. If shear forces are applied to the gel as a result of packaging, the gel may be damaged, resulting in a fractured and unacceptable finished product, as has been described in U.S. Pat. No. 5,518,745 to Thota et. al as follows:
A problem with utilizing a continuous extrusion process to obtain a set extrudate is that when the product begins to set within the extruder, the possibility of degradation and physical break up of the extrudate during conveyance increases after the transition of the mixed ingredients from a liquid phase to a highly viscous solid or gel phase. The high viscosity of the setting gel increases shear forces throughout the extrudate as it is conveyed through the extruder. When the final mixture of the product is shear sensitive, the extrudate tends to degrade and break apart, at least sporadically, as it is conveyed through. the extrusion die, significantly limiting the ability to continuously convey, shape, form and cut the extrudate in an efficient and continuous manner.
(Col. 2, lines 7-20).
Delaying gel formation until the product is in a packaged and finally-formed state, however, may present problems during earlier stages of the packaging process. The product may simply be too thin or runny to package properly as it passes through packaging machinery, such as high-speed slice forming equipment. Thus, problems have been encountered in packaging food products that are either relatively low or high in viscosity.
Some packaging equipment has been designed to move slowly enough to accommodate gel formation. With increasing food plant size and increased equipment automation, line speeds have increased. Packaging equipment requires fast through puts to justify equipment costs. The food products made in these plants must not only be acceptable upon shipment, but must also be able to tolerate these rapid line speeds. Packaging equipment has been specially designed to allow the passage of solid state food products (see, e.g., the Thota patent, describing the use of a low viscosity fluid continuously flowing over a channel in an extrusion die to induce laminar flow of a gelled food product). However, it would be more economical to provide food products designed to progress through existing packaging machines than to specially design machines to handle fluid food products.
In addition, packaging materials or operations may require the food product itself to provide its own structural support, e.g., when a particular shape, such as a cookie or candy, is extruded and deposited on a tray.
Various gel shapes have been described in the patent literature. See, e.g., the Bogdan patent; EPO Patent Application 99-13 0904703 to Fassin et. al., xe2x80x9cSlice-shaped filling for sandwichesxe2x80x9d; U.S. Pat. No. 5,417,990 to Soedjak, describing multi-layered gelled products; and U.S. Pat. No. 5,783,241 to Bocabeille et. al., xe2x80x9cMethod For Producing Cylindrical Gel Food Productsxe2x80x9d, in which gelling is induced internally and externally of an extruded food product using a calcium bath. However, no provision for commercial high-speed processing and packaging of a food product using a multi-stage gel or thickener appears to be described.
Accordingly, it is an object of the present invention to provide a gelling or thickening system which will introduce sufficient integrity to a food product so as to facilitate packaging of the food product.
It is another object of the invention to provide a multi-stage gelling/thickening system that provides the food product with sufficient viscosity during all relevant stages of food product formation and/or food product packaging, while also imparting desired shape and texture characteristics to the food product.
It is a further object to provide a gelling/thickening system adaptable for use with existing packaging machines, such as extruder machines for packaging individual slices of food items, without the need to specially re-design such machines.
It is yet another object to provide a gelling/thickening system which provides a food product with desired viscosity to allow proper weight control over the food product packages.
It is still another object to provide a multiple-stage gelling/thickening system which is consumable, cost-efficient and environmentally friendly.
The following terms are used in the claims of the patent as filed and are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language.
xe2x80x9cGelxe2x80x9d is used here as that term is normally understood to those of ordinary skill in the art, and refers to a colloid in a form more solid than a sol.
xe2x80x9cGelling agentxe2x80x9d means a substance(s) that causes or facilitates the formation of a gel.
xe2x80x9cSetxe2x80x9d means for a gelled product to reach a substantially constant viscosity.
xe2x80x9cThickenersxe2x80x9d mean constituents for increasing the viscosity of a food product, including gelling and non-gelling agents.
xe2x80x9cPackagexe2x80x9d means any encapsulation or covering for a food product.
xe2x80x9cCompatiblexe2x80x9d or xe2x80x9cCompatibilityxe2x80x9d means that two or more gels or thickening agents present in the same food product will not interfere with the: gelling or thickening process of the other(s) in a manner that is substantially deleterious to packaging of the food product or its consumer appeal.
xe2x80x9cFood Productxe2x80x9d means any edible or consumable product.
xe2x80x9cJellyxe2x80x9d means any gelled food product, including all types of jellies, jams, preserves, marmalades, fruit butters, desert gels, gelatin slices, and the like.
xe2x80x9cDisruptxe2x80x9d, xe2x80x9cdisruptingxe2x80x9d, xe2x80x9cdisruptionxe2x80x9d or xe2x80x9cdisruptedxe2x80x9d means an interference with the texture of the thickening or gelling agent composition or food matrix which occurs during or after the food product has been initially inserted within a packaging material.
xe2x80x9cTexturexe2x80x9d means the physical sensation of a food product as it interacts with the human senses, including its appearance and its mouth-feel upon mastication.
xe2x80x9cEnablexe2x80x9d or xe2x80x9cenablingxe2x80x9d means to simply provide an environment for a reaction or change as well as to cause that change using chemical or other means.
The objects mentioned above, as well as other objects, are solved by the present invention, which overcomes disadvantages of prior art thickener or gelling systems, while providing new advantages not previously obtainable.
This invention has its genesis in the surprising finding that two or more gelling or thickening agents may be added to a food product, with a first (e.g., rapid-setting) gel or thickening agent providing the necessary viscosity for entry and shaping of the food product in continuous packaging equipment. The first gel or thickening agent may be deformed and dynamically disrupted through this packaging process. This disruption, as may be evidenced by an inconsistent, non-uniform, lumpy and/or granular texture formation, for example, consisting of a gel-phase and a viscous liquid phase, is believed contrary to general practices in gelled food manufacturing, which typically require a quiescent thickener/gel setting. A second (e.g., slow-setting) gel or thickener may be used to xe2x80x9cmaskxe2x80x9d or limit this disruption, allowing the formation of a firm, elastic, continuous food product.
In one embodiment of the present invention, a food product to be continuously packaged by a packaging machine is to be provided with a desired texture. The food product includes a multi-stage thickening composition, including preferably compatible first and second thickening agents. The first thickening agent, which may but need not be a gelling agent, increases the viscosity of the food product so as to facilitate packaging of the food product. In other words, as one example, the food product viscosity is sufficiently increased by the first thickening agent to avoid the problem shown in FIG. 5. The first thickening agent is then disrupted in a manner that interferes with the provision of the desired texture of the food product. The second thickening agent permits the food product to be provided with the desired texture following the disruption of the first thickening agent.
In a preferred embodiment, the food product takes the form of a slice wrapped in a plastic film. In a particularly preferred embodiment, the food product slice is hermetically sealed within the plastic film.
As non-limiting examples, food products which may find advantageous use with the principles of the present invention include jelly, food sauces and dessert gels.
As non-limiting examples, first or more rapid thickening or gelling agents which may be used to advantage with the present invention include pectin and Konjac gum. Also as a non-limiting example, a second or slower-setting thickening or gelling agent which may be used to advantage with the present invention is gelatin.
In a preferred embodiment, using a vertical form and fill machine for packaging individually wrapped food products in slices, the viscosity of the food product immediately prior to insertion of the food product within the plastic packaging film is about 5,000 centipoise or less, while the viscosity of the food product following gelling of either first or second gelling agents is about 100,000 centipoise or greater.
The present invention also includes a process for forming a food product to be packaged in a continuous packaging operation, and with a desired shape and texture. First, a food product that includes a multi-stage thickening composition with first and second thickening agents is dispersed within other constituents of the food product. Heating of the food product mixture may also occur at this time. The. first thickening agent is permitted to increase the viscosity of the food product so as to facilitate shaping and packaging of the food product. The first thickening agent is then disrupted in a manner that interferes with provision of the desired texture of the food product. Next, the second thickening agent is allowed to provide the food product with the desired texture following the disruption of the first thickening agent. Cooling of the first and second thickening agents may be provided during their thickening or gel formation to enhance or accelerate same.
In preferred embodiment, either the first or second thickening agents, or both, constitute gelling agents.
In preferred embodiments, the increase in viscosity of the food product caused by one or both of the thickening agents may be enhanced by a decrease in temperature.
In one embodiment, chemical additives may be added to the heated food product matrix to enhance or accelerate thickening or gel formation. These chemical additives are preferably divalent cations. In a particularly preferred embodiment, calcium chloride is used.